Had a code come up this morning going to work p0455 what the H is that. I disconnected the neg and turned the key three times and no more code, it will come back in time, but should get it fixed.

 

I believe that code is for a medium EVAP leak. I'd check you vacuum hoses real good, including the ones under the truck. Odds are thats where they will be.

 

According to the code list on this forum, it's actually a large leak. I had the same problem about 2 weeks ago and the hose had come loose from the charcoal canister. If you crawl under the truck by the driver's side door, it's a black plastic box with a couple of hoses connected to it.